低阻型烟风道数值模拟及内部流场的优化设计研究
发布时间：2019-05-05 17:35
【摘要】：随着我国经济大跨步的发展,能源消耗和环境污染问题也随之加重。国家越来越重视工业生产的节能减排。我国能源结构决定了燃煤电厂在电力行业有着重要的地位。如何最大限度的降低电厂排放烟尘所造成的污染一直以来都是极为重要的研究课题。其中提高除尘器的除尘效率就是缓解污染的有效手段之一,而流场分布的均匀程度是电厂除尘器除尘效率影响因素中的一项重要指标。同时,提高流场分布的均匀程度还有利于降低烟道的磨损,延长烟道的使用寿命。燃煤火电厂烟道内部构件的设计好坏关系到烟道内流场分布均匀程度。而弯头作为烟道中较为常用也较为特殊的构件已经被国内外学者从不同角度进行了多方面研究。但纵观专家学者的研究成果,鲜见对实际工程中带有内撑杆件的大型烟道进行的模拟研究,而内撑杆件对烟道烟气的分布却有着十分重要的作用,并不能完全忽略。因此,本文以工程中常用的规范标准烟道及CE方案烟道两种烟道为原型,建立它们的弯管与直管段组合以及弯管与弯管组合模型,并借助计算流体动力学软件Fluent模拟除尘器模型前烟道的速度和压力分布。随后在原管道基础上添加导流板进行模拟,进而优化原管道内部结构的设计。研究结果表明:内撑结构是造成烟道局部阻力损失的主要原因,阻力损失所占份额均为总阻力损失的50%左右;弯管与直管组合形式的烟道中,规范标准内撑结构优于CE方案的内撑结构,而对于弯管与弯管组合来说两种内撑方案区别不明显;常规导流板的布置可以提高烟道流场分布的均匀性,但是更需要一种既能导流又能起到支撑作用的构件来代替;在所得基础研究的结论基础上,设计了以“变外部急转为内部缓转”为设计理念的新型烟道,使得出口烟气走向更加均匀。弯管与直管组合的新型烟道压力损失与原模型相比降低约40%。弯管与弯管组合的新型烟道也在不同方面获得了优于原方案的结果。所得结论可应用于工程选型,为管道内的支撑件及导流部件的布置提供较为可靠的理论依据及方法指导。
[Abstract]:With the rapid development of China's economy, energy consumption and environmental pollution are becoming more and more serious. The country is paying more and more attention to the energy saving and emission reduction of industrial production. China's energy structure determines that coal-fired power plants play an important role in the power industry. How to minimize the pollution caused by smoke and dust emission from power plants has always been a very important research topic. Improving the dust removal efficiency of the dust collector is one of the effective measures to alleviate the pollution, and the uniformity of the flow field distribution is an important index of the factors affecting the dust removal efficiency of the dust collector in the power plant. At the same time, increasing the uniformity of the flow field distribution is beneficial to reduce the wear and tear of the flue and prolong the service life of the flue. The design of internal components of flue in coal-fired power plant is related to the uniformity of flow field in flue. As a common and special component in flue, elbow has been studied from different angles by scholars at home and abroad. However, throughout the research results of experts and scholars, few simulation studies have been carried out on large-scale flue gas with internal strut members in practical engineering, but the internal strut members play a very important role in the distribution of flue gas, and cannot be completely ignored. Therefore, taking the standard flue and CE scheme as prototypes, the combination of bend and straight pipe and the combination model of bends and bends are established in this paper. The velocity and pressure distribution of the flue in front of the precipitator model are simulated with the aid of computational fluid dynamics software Fluent. Then a diversion plate is added to the foundation of the original pipeline to simulate and optimize the design of the internal structure of the original pipe. The results show that the internal brace structure is the main cause of the local resistance loss of flue, and the share of resistance loss is about 50% of the total resistance loss. In the combination of bent pipe and straight pipe, the standard internal brace structure is better than the inner brace structure of CE scheme, but the difference between the two brace schemes is not obvious for the combination of bent pipe and straight pipe. The layout of conventional diversion plate can improve the uniformity of the flow field in the flue, but it needs a kind of component which can not only guide the flow but also play a supporting role. On the basis of the conclusion of the basic research, a new type of flue gas is designed, which is based on the design idea of "changing the external urgency to the internal slow rotation", which makes the outlet flue gas more uniform. Compared with the original model, the pressure loss of the new flue in the combination of bends and straight pipes is reduced by about 40%. The results of the combination of bends and bends are better than those of the original scheme in different aspects. The conclusions obtained can be applied to engineering selection and provide reliable theoretical basis and method guidance for the layout of the support and diversion components in the pipeline.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU834.6
本文编号：2469778
[Abstract]:With the rapid development of China's economy, energy consumption and environmental pollution are becoming more and more serious. The country is paying more and more attention to the energy saving and emission reduction of industrial production. China's energy structure determines that coal-fired power plants play an important role in the power industry. How to minimize the pollution caused by smoke and dust emission from power plants has always been a very important research topic. Improving the dust removal efficiency of the dust collector is one of the effective measures to alleviate the pollution, and the uniformity of the flow field distribution is an important index of the factors affecting the dust removal efficiency of the dust collector in the power plant. At the same time, increasing the uniformity of the flow field distribution is beneficial to reduce the wear and tear of the flue and prolong the service life of the flue. The design of internal components of flue in coal-fired power plant is related to the uniformity of flow field in flue. As a common and special component in flue, elbow has been studied from different angles by scholars at home and abroad. However, throughout the research results of experts and scholars, few simulation studies have been carried out on large-scale flue gas with internal strut members in practical engineering, but the internal strut members play a very important role in the distribution of flue gas, and cannot be completely ignored. Therefore, taking the standard flue and CE scheme as prototypes, the combination of bend and straight pipe and the combination model of bends and bends are established in this paper. The velocity and pressure distribution of the flue in front of the precipitator model are simulated with the aid of computational fluid dynamics software Fluent. Then a diversion plate is added to the foundation of the original pipeline to simulate and optimize the design of the internal structure of the original pipe. The results show that the internal brace structure is the main cause of the local resistance loss of flue, and the share of resistance loss is about 50% of the total resistance loss. In the combination of bent pipe and straight pipe, the standard internal brace structure is better than the inner brace structure of CE scheme, but the difference between the two brace schemes is not obvious for the combination of bent pipe and straight pipe. The layout of conventional diversion plate can improve the uniformity of the flow field in the flue, but it needs a kind of component which can not only guide the flow but also play a supporting role. On the basis of the conclusion of the basic research, a new type of flue gas is designed, which is based on the design idea of "changing the external urgency to the internal slow rotation", which makes the outlet flue gas more uniform. Compared with the original model, the pressure loss of the new flue in the combination of bends and straight pipes is reduced by about 40%. The results of the combination of bends and bends are better than those of the original scheme in different aspects. The conclusions obtained can be applied to engineering selection and provide reliable theoretical basis and method guidance for the layout of the support and diversion components in the pipeline.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU834.6
【引证文献】
相关期刊论文 前2条
1 章华熔;林翔;叶兴联;吴桂平;;流场优化消除烟道振动研究[J];电力科技与环保;2018年02期
2 陈炼非;胡南;;风道入口段的数值模拟及优化设计[J];沈阳工程学院学报(自然科学版);2017年02期
，本文编号：2469778
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